"Ebadi, death to the witch of America," reads the scrawl on the garage door, the word "witch" misspelled in Farsi. Nearby is another message: "Shame on the holder of the pen of the enemy."

That action, along with the closing of Ebadi's Center for Human Rights Defenders in late December, is the latest volley in a broader challenge by authorities against campaigners of all kinds, from labor leaders and journalists to students and women trying to redress discriminatory laws by gathering 1 million signatures.

For more than two years, Iranian security chiefs have stated that the biggest threat to the Islamic Republic is from inside Iran. Activists are often accused of endangering "national security," and in the pay of arch foes Israel or the US to foment a "Velvet Revolution" against the regime.

"The people who accuse me of working with the US know themselves that it is not right," says Ebadi in an interview, noting that she has received numerous threats to her life from hard-line critics.

The tens of millions of dollars the US has set aside in recent years for "pro-democracy" activities have instead "damaged the human rights situation in Iran," says Ebadi, by giving authorities a pretext for suspicion.

"This will not lead me to leave Iran or to give up my work," says Ebadi. "What I am doing is based on the law, and they can't stop me…. A government that is powerful is more open to criticism. [This one] is scared."

Some analysts in Iran say the government of President Mahmoud Ahmadinejad has reason to worry, given years of Washington talk about "regime change" in Iran. The seed cash for today's American "pro-democracy" money, in fact, was $18 million pushed by former Speaker of the House Newt Gingrich (R-Georgia) in 1996 for a "covert CIA operation" aimed at toppling the government.

Home-grown activists

"The problem is, Ebadi and those people going for the signatures are not seen as home-grown activists," says Seyed Mohammad Marandi, head of North American Studies at the University of Tehran. "[People] think Western interests are behind it…. So they feel they have no place here. They are seen as people getting funding from abroad."

"They don't like activism at all, and not just women, but trade unions and others," says a European diplomat in Tehran, who requested anonymity. "They want to tell the world: 'You can put pressure on us, it does not matter.' "

The UN General Assembly in December passed a resolution expressing "deep concern at serious human rights violations" in Iran. Officials say they adhere strictly to Iran's Constitution and that the execution of 346 offenders in 2008, according to an Amnesty International count) was in accord with the law.

In a February report, Amnesty described "arbitrary arrests and harassment" of more than 220 people in the previous three months, noting that it was ahead of the June presidential election.

Among the most active campaigns is a grassroots effort to reform laws that discriminate against women, called the One Million Signatures Campaign. Volunteers are often detained by police; high-profile protests in the past have led to scores of arrests.

"They know our population is 70 million, so if we gather 1 million signatures, it is nothing," says leader Parvin Ardalan, speaking in her tiny Tehran apartment. "The important thing is, the action we do is increasing consciousness in society and thinking of equality."

Steps taken against the group have raised its profile, including numerous court cases and "national security" charges. The website has been blocked 20 times. A spike of interest came when Ms. Ardalan was named winner of the 1997 Olof Palme prize, but prevented from collecting it when she was ordered off the plane moments before takeoff.

Ardalan's passport has not yet been returned. The prize citation on her wall is for "making the demand for equal rights for men and women a central part of the struggle for democracy in Iran." Ardalan was among four activists sentenced to six months in jail last September for "spreading propaganda." Her case is now under appeal.

The campaign also won the 2009 Simone de Beauvoir prize for women's freedom in January, but the group decided, given the current atmosphere in Iran, that they could not accept the €30,000 in prize money. The campaign fields volunteers who hand out leaflets about the discrepancies between men's and women's legal rights and asks people to sign a petition for change.

Vote to let women inherit land

A month ago, parliament voted to let women inherit land from husbands, one of several steps – which last year included vetoing changes in the marriage law that would have made polygamy easier for men – that are starting to slowly expand women's rights. "We are now powerful. Of course, we didn't do anything, but they are afraid of us," says Ardalan, noting that so far they may have 200,000 signatures. "We are changing discourse on women. They attack us ... but they must adhere to the law. Of course we couldn't gather 1 million signatures, but 1 million people know about us."